Arkansas Code Title 27. Transportation § 27-51-302. Roadways divided into lanes

(1) A vehicle shall be driven as nearly as practical entirely within a single lane and shall not be moved from the lane until the driver has first ascertained that movement can be made with safety; and

(2) Official signs may be erected directing slower-moving traffic to use a designated lane or allocating specified lanes to traffic moving in the same direction, and drivers of vehicles shall obey the directions of every such sign.